Oral Antioxidant Vitamins and Magnesium Limit Noise-Induced Hearing Loss by Promoting Sensory Hair Cell Survival: Role of Antioxidant Enzymes and Apoptosis Genes.
Level 5 - mechanism / opinion, no new human data
Preclinical animal model without human clinical data
PubMed 33255728 · doi:10.3390/antiox9121177
What was done
Researchers evaluated whether oral administration of vitamins A, C, E, and magnesium (ACEMg) protects against noise-induced hearing loss in rats. Auditory function was assessed using auditory evoked potentials, sensory outer hair cell survival was quantified, and cochlear expression of antioxidant enzymes and apoptosis-related genes and proteins was measured at 1, 10, and 30 days post-noise exposure using quantitative PCR and immunocytochemistry.
What was found
Oral ACEMg reduced auditory threshold shifts and increased sensory outer hair cell survival after noise-induced hearing loss. Cochlear expression of glutathione peroxidase-1 increased at day 1 and catalase increased at day 10. Pro-apoptotic caspase-3 and Bax levels were diminished at 10 and 30 days, respectively, whereas anti-apoptotic Bcl-2 levels increased at day 10. The abstract reported these directional changes without providing numerical values or effect sizes.
Why it matters
This study provides preclinical evidence that oral antioxidant vitamins and magnesium can reduce acoustic trauma and hair cell loss in rodents. It outlines specific temporal changes in cochlear antioxidant defenses and apoptotic pathways associated with oral otoprotection.
Limits
This was an animal study conducted in rats, so findings may not translate directly to human noise-induced hearing loss. The abstract does not report the total sample size (n), specific noise exposure parameters, or numerical effect sizes with confidence intervals.
Cited by
- supports Magnesium in the cochlear endolymph is depleted by loud sound, and magnesium supplementation protects against acoustic trauma and permanent hair cell loss.